Minnesota Inventors Hall of Fame


Dr. Patrick R. Gruber - 2003 Inductee

(1960 - ) Dr. Gruber is credited with inventing a commercially viable process for producing polylactic acid (PLA), a biodegradable plastic made from corn. He is named co-inventor on 48 United States patents related to the production of PLA. He and his wife Sally, also a chemist, first created plastic from corn kernels by brewing a batch of PLA on their kitchen stove without using any additives or solvents. PLA was first identified in the 1920's, when Wallace Carothers, the inventor of nylon, worked on it at DuPont. Chemical giants had spent decades trying to find a renewable and environmentally safe raw material to make into plastic. Until Gruber’s discovery in 1989, no one had discovered out how to make PLA from plant starches with the right properties and inexpensively enough for large scale production.

Using the process Gruber developed, PLA can be produced from corn kernels and other renewable, cheap and ecologically-friendly raw materials, such as corn stalks or wheat straw. This polymer is used in place of petroleum based resin in the manufacture of plastic, without sacrificing price or performance. It has many advantages over conventional, petrochemical based plastics. Its performance matches or exceeds conventional plastics, but it is also biodegradable, composting into harmless carbon dioxide and dirt. In most forms it is 100 percent recyclable. It is produced using 30% to 50% less energy than conventional, petrochemical produced plastic, resulting in 30% to 50% fewer gases that contribute to the greenhouse effect and global warming. Its use lessens dependence on foreign oil, and provides another market for corn grown by American farmers.

Dr. Gruber was instrumental in forming Cargill Dow LLC to develop, manufacture and sell products manufactured with polylactic acid. After more than a decade of work and investment of half a billion dollars, a new plant began producing PLA in Blair, Nebraska. Cargill Dow has estimated that 1.4 billion barrels of oil were conserved the first year of the plant’s operation.

NOTE: These biographies have been compiled from information accompanying the nomination form submitted to the Minnesota Inventors Hall of Fame, information available on the Internet and from a variety of other sources.